Take advantage of the Iditarod for teaching about the position of the sun in the sky. In this lesson, students plot on a map the hours of daylight in different cities/locations around the country or the world.

The Activity
According to timeanddate.com, race day in Anchorage will afford mushers a little more than 10 hours of daylight. How does that compare to the amount of daylight on the same day where you live? How does it compare to other places in your country or the world? (Residents in Chicago will experience about 11 hours, 15 minutes of daylight. In Miami, people will have about 11 hours, 45 minutes of daylight.)

For the purpose of this activity, daylight is determined for any location by calculating the difference between the official times of sunrise and sunset in that location. If the sun rises in Anchorage at 8:02 a.m. on March 1 and sets at 6:23, the city experiences 10 hours, 21 minutes of daylight.

Provide students with a blank outline map. Depending on your grade level, you might focus the lesson on a map of the United States, North America, or the world.

You can find a nice variety of outline maps in the following Web resources:

Identify for students a group of locations -- including Anchorage, Alaska (the starting point for the Iditarod), and your own town or a nearby city -- that you would like them to plot on the map. For example, if you are going to have students plot the amount of daylight in cities around the United States on a North America outline map, you might have them determine the amount of daylight on the start date of the Iditarod in the locations listed below. (Approximate amount of daylight for March 1 appears in parentheses.)

Anchorage, Alaska (10 hours, 20 minutes)

Your Town, USA (times will vary)

Atlanta, Georgia (11 hours, 30 minutes)

Chicago, Illinois (11 hours, 15 minutes)

Denver, Colorado (11 hours, 20 minutes)

Los Angeles, California (11 hours, 25 minutes)

Miami, Florida (11 hours, 35 minutes)

Minneapolis, Minnesota (11 hours, 10 minutes)

Seattle, Washington (11 hours, 0 minutes)

Washington, DC (11 hours, 20 minutes)

If you teach older students, you might have them plot daylight in ten cities around the world.

When students have completed their maps, discuss the data and its placement on the map. The maps will provide a visual representation of the science behind day and night. Students will see that locations in the northern parts of the United States have less daylight on any given day than the locations in the southern parts of the country because the northern cities are farther from the sun.

Sunrise/Sunset Resources
Where will students go to collect the information about the amount of daylight in the locations you provide?

Students in grades 3-4 might use timeanddate.com; they can use the World Time Search search engine by selecting North America and typing in the name of the city.

Middle grade students might search for sunrise and sunset times on the Weather pages of Web sites of major newspapers or TV stations in the selected cities.

Middle grade and older students might use the Sunset Calculator; they type in longitude and latitude coordinates for selected locations to access data.

Extension Activities

Have students compare the hours of daylight on race day in Anchorage and in their hometown in a side-by-side bar graph. To create the graph, students can use art supplies, graphing software, or the online Create a Graph tool.

Have students create a table and a simple line graph to illustrate the amount of daylight throughout the year; each student might create a table/graph for the same location -- your town, perhaps -- or you might assign a different location to each student. (See a sample table and line graph[it will take some time for the archived version of this graph to load] created by students at Weller Elementary School in Fairbanks, Alaska.) To create the graph, students can use art supplies, graphing software, or the online Create a Graph tool.

Assessment

Students write three statements that tell what they learned from the mapping activity.